The computer restarts on its own
My PC keeps restarting randomly without any warning.
Written by The CommonFixes team · fact checked by CommonFixes review desk
Last updated
Short answer
Heat, an unstable power supply, or a failing memory stick are the usual causes. A restart with no message points to hardware more than software. The quickest thing to try first: stop the automatic restart so you can read the error — Search for View advanced system settings, open Startup and Recovery Settings, and untick Automatically restart. The next crash will show a message you can act on. Most people are done in about 25 minutes.
Full walkthrough below: 5 steps for Windows and Mac, rated medium.
Sounds like this
- •Sudden restarts with no message
- •Happens under heavy use
- •No blue screen shown
Why it happens
Heat, an unstable power supply, or a failing memory stick are the usual causes. A restart with no message points to hardware more than software.
Work through these in order
0% done- 1
Stop the automatic restart so you can read the error
Search for View advanced system settings, open Startup and Recovery Settings, and untick Automatically restart. The next crash will show a message you can act on.
- 2
Check temperatures
Install HWMonitor and watch the processor temperature during normal use. Shutdowns above ninety-five degrees Celsius are heat protection working as intended.
- 3
Clean out dust
Blow the dust out of the fans and vents. On a desktop, open the side panel and clear the heatsink and the power supply grille.
- 4
Test the memory
Run Windows Memory Diagnostic, or the free MemTest86 from a USB stick for a stricter overnight test.
- 5
Check the power
On a desktop, an ageing power supply causes exactly this. On a laptop, test a different charger. Also avoid unreliable extension leads.
If none of that worked
Look in Event Viewer under Windows Logs, System, and search for Kernel-Power event 41. The details around it point to the failing part.
Did this fix work for you?
A quick thumbs up helps other readers find the guides that actually work.
Share this fix
Related fixes worth reading
Chosen automatically from the 157 guides on CommonFixes, based on how closely they match this problem.
Windows stops with error 0xc00000e
How do I fix error code 0xc00000e, the connection to the device was lost?
Blue screen with a sad face
My computer keeps showing a blue screen and restarting. How do I stop it?
The BIOS update failed
Why does my laptop say 'BIOS update failed'?
The computer wakes up on its own at night
My PC turns itself on after I put it to sleep. How do I stop that?
A message says no bootable device
It says no bootable device found or operating system not found. Is my data gone?
Stuck on the maker logo forever
My computer stays on the brand logo screen and never loads Windows.
Still not it? Browse every fix or see more in will not start.
Who wrote this and how we checked it
The CommonFixes team
Writer and researcher
We are a small group of people who spend our days repairing laptops and desktops for family, friends and small offices. Every guide here starts with a problem someone actually brought to us, and we only write down the steps that put the machine right.
- Everyday repairs
- Windows and Mac
- Plain language
CommonFixes review desk
Technical editor
Before a guide goes live, a second person walks through it on a real machine and checks each instruction against the maker's own support pages. Anything we cannot confirm is removed rather than guessed at.
- Fact checking
- Safety warnings
- Source links
This guide was last updated on 10 August 2026. If a step no longer matches what you see on screen, tell us on the contact page and we will test it again.
A gentle reminder: back up anything you cannot afford to lose before major repairs. If a step ever feels risky, stop and ask a technician. There is no shame in that.